- Compare and contrast precision, accuracy, systematic errors, and random errors. 
- Identify sources of random and systematic errors.
- Explain how systematic and random errors affect precision, accuracy and uncertainty.
- Calculate and report uncertainties in measurements. 
Measurement Error (also called Observational Error) is the difference between a measured quantity and its true value. It includes random error (naturally occurring errors that are to be expected with any experiment) and systematic error (caused by a mis-calibrated instrument that affects all measurements)
random errors are fluctuations (in both directions) in the measured data due to the precision limitations of the measurement device. Random errors usually result from the experimenter's inability to take the same measurement in exactly the same way to get exact the same number
refers to the closeness of two or more measurements to each other
refers to the closeness of a measured value to a standard or known value
Amount by which a measured, calculated, or approximated value could be different from the actual value
each of the digits of a number that are used to express it to the required degree of accuracy, starting from the first nonzero digit